A recent statement issued by the company said the mid-November extension was prompted by the alarming economic news of the past several weeks. (Click on "Chrysler" and "General Motors" for related news from the automakers.)

"We realize the uncertain economic climate could result in an employee reconsidering his or her decision," the statement said. "Because of that, we are extending the consideration period."

The buyout is offering workers up to $125,000 in hopes of reducing the workforce at two Tennessee factories by about 1,200 people. Nissan's Smyrna, Tennessee, assembly plant and its Decherd, Tennessee, engine plant employ about 6,600 people, not all of whom are eligible.

The automaker has been tight-lipped about the number of people who have expressed interest in the buyout. One company source said that more than twice as many people as expected—as many as 2,800 employees—initially opted to leave, surprising officials in the United States and Japan.

Steve Parrett, manufacturing spokesman at Nissan's Nashville headquarters, said he has not heard a specific number and that company officials would not discuss the numbers.

He acknowledged that the program "has been very well received."

The offer consists of a lump sum payment of $100,000 or $125,000, depending on tenure, plus a year of health coverage and a car purchase discount.

Workers can also opt to accept a buyout in 2009 or 2010, but for a reduced amount of money. According to the recent statement, employees opting for those later buyouts now have until next year to decide whether to accept.